Valve assembly for medical procedures

ABSTRACT

The invention relates to a valve used in medical procedures. More specifically the invention relates to an introducer sheath valve used in minimally invasive and conventional surgical procedures. The valve may accommodate a wide range of surgical implement diameters, shapes, and multiple implements without imposing the high frictional forces of known valves.

CROSS REFERENCE TO RELATED APPLICATIONS

This application claims priority to provisional application U.S. Ser.No. 61/058,744, filed Jun. 4, 2008.

BACKGROUND OF THE INVENTION

1. Field of the Invention

The invention relates to a valve assembly for medical procedures.

2. Discussion of the Related Art

Valve assemblies are used in many medical procedures. More specifically,introducer sheath valves are used in a wide variety of minimallyinvasive and conventional surgical procedures. For example, laparoscopicand arthroscopic surgical procedures are often performed through trocarassemblies, which include introducer sheath valves.

Current introducer sheath valves generally fall into two basiccategories: passive and active. A passive introducer sheath valvegenerally relies on the deformation of a resilient sealing body by theimplement inserted through the valve to form the desired fluid tightseal. Active valves include a mechanism that moves a sealing body intocontact with the traversing implement. An example of an active valvewould be constructed of a housing and a tubular resilient valve carriedwithin the housing. This valve requires a means for varying the pressurein the space within the housing but outside of the tubular valve inorder to urge the resilient valve to collapse inwardly to seal aroundthe implement.

Another example of an active valve is constructed of an elastomericsealing body, which will maintain hemostasis by contacting a surgicalimplement traversing the valve over a very small contact area. Theorifice is formed in the thin elastomeric membrane, which extendsradially inward from a torroidal balloon having a relatively rigid outerrim and a flexible inner portion. In this example, a vacuum is appliedwithin the torroidal balloon to pull the elastomeric membrane radiallyoutward for implement insertion. Sealing around the implement isactuated by applying a positive pressure within the torroidal balloonexpanding the balloon radially inward to block access through the valve.

While these and other valve designs are fairly tolerant of variousdiameters of surgical implements, all of the currently available valveshave significant limitation as to the variation in diameter, variationin shape of implement and how many implements which can pass through thevalve without damaging it and with optimal sealing properties. For thesereasons, it would be desirable to provide improved introducer sheathvalves for use in endovascular, laparoscopic and other surgicalprocedures. Such valves would preferably seal over a wide range ofsurgical implement diameters, shapes, and multiple implements withoutimposing the high frictional forces of known valves, regardless ofcross-sectional size or shape of the surgical implement traversing thevalve.

Although specifically discussed as an introducer sheath valve, theinvention encompasses other applications such as bariatric port access,medical injection port, vascular access port, valve for insertion sitessuch as feeding tubes or dialysis access port, etc.

SUMMARY OF THE INVENTION

A first embodiment provides an introducer sheath valve having an outertube and an inner tube comprised of a porous substrate with apressurizable space formed between the inner surface of the outer tubeand the outer surface of the inner tube.

A further embodiment provides an introducer sheath valve having an outertube and an inner tube with a thickness of about 0.0025 mm to about 1 mmwith a pressurizable space formed between the inner surface of the outertube and the outer surface of the inner tube.

An additional embodiment provides an introducer sheath valve having anouter tube and an inner tube comprised of ePTFE (expandedpolytetrafluoroethylene) with a pressurizable space formed between theinner surface of the outer tube and the outer surface of the inner tube.

Additional features and advantages of the invention will be set forth inthe description or may be learned by practice of the invention. Thesefeatures and other advantages of the invention will be realized andattained by the structure particularly pointed out in the writtendescription and claims hereof as well as the appended drawings.

It is to be understood that both the foregoing general description andthe following detailed description are exemplary and explanatory and areintended to provide further explanation of the invention as claimed.

BRIEF DESCRIPTION OF THE DRAWINGS

The accompanying drawings are included to provide a furtherunderstanding of the invention and are incorporated in and constitute apart of this specification, illustrate embodiments of the invention, andtogether with the description serve to explain the principles of theinvention.

In the drawings:

FIG. 1 is a perspective view of an introducer sheath which carries oneembodiment of the introducer sheath valve.

FIG. 2 is a cut away view of an introducer sheath which carries oneembodiment of the introducer sheath valve.

FIG. 2A is a cut away view of an introducer sheath which carries oneembodiment of the introducer sheath valve.

FIG. 3 is an expanded view of one embodiment of the introducer sheathvalve.

FIG. 4 is an end on view of one embodiment of the introducer sheathvalve.

FIGS. 5A-C illustrate examples of a porous substrate.

FIGS. 6A-C illustrate magnified examples of a surface of a poroussubstrate.

FIGS. 7A-C illustrate magnified examples of a surface of a poroussubstrate with a polymer filling openings or pores in the substrate.

FIG. 8 is a cut away view of an introducer sheath which carries oneembodiment of the introducer sheath valve.

DETAILED DESCRIPTION OF THE ILLUSTRATED EMBODIMENTS

A first embodiment comprises an introducer sheath valve constructed ofan outer tube and an inner tube comprised of a porous substrate with apressurizable space formed between the inner surface of the outer tubeand the outer surface of the inner tube.

FIG. 1 shows one embodiment of the introducer sheath valve 100.Introducer sheath valve 100 assembly may be attached to an introducersheath 102. Sheath 102 may be manufactured of either fluorinatedethylene propylene (FEP) or extruded high density polyethylene or anyother material with suitable biocompatible and mechanical properties.One of skill in the art can readily appreciate that there are a widevariety of potential materials that may be used to facilitate thepresent invention. Sheath 102 may be of any size but is preferably sizedfrom about 12 to 26 Fr. On the proximal most end of the sheath 102 isthe threaded adapter 104. The threaded adapter 104 may be manufacturedof any biocompatible plastic or any biocompatible metal with suitablebiocompatible and mechanical properties. Threaded adapter 104 may beattached to sheath 102 by a variety of means which include but are notlimited to adhesives such as polyurethane adhesives, quick settingcyanoacrylate adhesives, or ultraviolet cured adhesives. Other means toattach threaded adapter 104 to sheath 102 may include ultrasonicwelding, interference fit, thermal bond and insert molding. One of skillin the art can readily appreciate that there are a wide variety ofpotential means for attaching threaded adapter 104 to sheath 102. Thedistal end of the front fitting 106 may be attached to the proximal endof the threaded adapter 104. The threaded adapter 104, front fitting106, snap ring 108 and snap ring 108′ with fill port 112 may bemanufactured of any biocompatible metal or plastic with suitablebiocompatible and mechanical properties. Snap ring 108 and snap ring108′ with fill port 112 will be discussed further. Front fitting 106 maybe attached to threaded adapter 104 with similar means as described inthe attachment of threaded adapter 104 and sheath 102. Of the manyfeatures and attributes of front fitting 106, a few are outlined in thefollowing description. Front fitting 106 is designed to enable a user togrip the device securely. Gripping may be aided by protrusions 107 onthe lateral sides of the fitting 106. These protrusions 107 may be madeof a similar material as that of the fitting 106 or may be made of amaterial with a high coefficient of friction or of a material morecompliant than that of front fitting 106. These protrusions may also bemade with grating, a roughening, a raised company logo or design, orstriations in the surface in conjunction with the material listed aboveto further aid in the gripping of the device. These features on thesurface of front fitting 106 may also be used to aid in gripping withoutthe use gripping protrusions 107 and may be applied directly to thelateral surface of front fitting 106. Front fitting 106 also includesthe feature of a flush port 109 with fitting. The function and use of aflush port 109 and fitting is commonly known in the arts.

As illustrated in FIG. 2, a cross-section of FIG. 1, and FIG. 3, anexploded view of FIG. 1, the outer sheath assembly may be constructed ofa snap ring 108, an outer tube 110, and a snap ring 108′ with fill port112. As discussed previously, snap ring 108 and snap ring 108′ with fillport 112 may be constructed of any biocompatible metal or plastic withsuitable biocompatible and mechanical properties. Fill port 112 may belocated at any point along snap ring 108 or 108′. Outer tube 110preferably has the feature of a sealing lip 204. Sealing lip 204 aids inthe secure fastening of snap ring 108 and snap ring 108′ with fill port112 to outer tube 110. Sealing lip 204 also provides a seal betweentubes 110 and 200. Outer tube 110 may be attached to snap ring 108 andsnap ring 108′ with fill port 112 by a variety of methods. Thepreferable method for connecting the parts is that of insert molding ascommonly practiced in the art. Other methods of attachment could includeinterference fit, adhesion or adhesives, ultrasonic welding and thermalbonding. Outer tube 110 may be constructed of any elastomer, latex orpolycarbonate with desirable mechanical and biocompatible properties. Inone embodiment, outer tube 110 comprises silicone and has a hourglassshape when not pressurized. When pressurized, the hourglass shape ofouter tube 110 becomes distended to indicate a desirable pressure in thepressurizable space 206. Pressurizing methods and means will bedescribed later. This feature of outer tube 110 enables the user of adevice to easily and quickly identify the optimal pressure for thedevice.

FIGS. 2 and 3 also show an inner tube 200. Inner tube 200 may be formedwith a ring 202 on each end of the inner tube 200. Inner tube 200 may beconstructed of any very thin, strong, drape-able material such as ePTFE,fabrics, silk, or Kevlar® brand fiber. These materials may be used as asingle layer construct or a multi-layer construct. In one embodiment,inner tube 200 can be formed of a thin porous substrate, ePTFE similarto that described in U.S. Patent Publication No. 2007/0012624 A1 or U.S.Patent Publication No. 2008/0053892 A1. This construct may be comprisedof multiple layers of ePTFE that may be filled or imbibed with apolymer. The filling or imbibing polymer may be the same as theconstruct or may be a different polymer. One construct can be similar tothat disclosed in U.S. Pat. No. 7,049,380. Porous substrateconfigurations will be further discussed with the description of FIGS.5A-C, FIGS. 6A-C and FIGS. 7A-C.

FIGS. 2 and 3 illustrate rings 202 on the ends of inner tube 200. Rings202 are used to create a stiff member to aid in attachment of inner tube200 to front fitting 106 and to rear fitting 208. Rings 202 may be madeof any material with desirable biocompatible and mechanical properties.Rings are preferably made of fluorinated ethylene propylene (FEP). Innertube 200 with attached rings 202 may be inserted through the outer tube110 and attached to the protruding end of front fitting 106. Snap ring108 may then be attached to front fitting 106 with an adhesive, butother suitable attachment methods will suffice. The remaining free ring202 may then be attached to the protrusion on rear fitting 208. Snapring 108′ with fill port 112 may then be snapped onto rear fitting 208.Methods for attaching snap ring 108′ with fill port 112 and rear fitting208 are similar to those describe previously. Materials used tomanufacture both snap ring 108′ with fill port 112 and rear fitting 208have been discussed previously.

FIG. 2A shows a embodiment in which pressurizable space 206 is filledprior to use and then fill port 112 is stopped with plug 207. Thisembodiment has largely the same components as shown in FIG. 2 with theaddition of plug 207.

FIG. 4 illustrates an end on view of the device showing a collapsedinner tube 200. Snap ring 108′ with fill port 112 has a feature thatallows pressurizable space 206 to be filled to a sufficient pressure tocause the inner tube 200 to collapse. Pressurizable space 206 may befilled with any suitable material or materials. For example,pressurizable space 206 may be filled with one or more of the followingsubstances: air, silicone, water, saline solution, low volatilitybiocompatible liquids, glycerin, propylene glycol, polyethylene glycol,compressible foam, elastomeric spheres, and crosslinked silicone gels.

Shown in FIGS. 5A through C are perspective views of various poroussubstrates. Porous substrates can have various shapes or forms that aresuited for particular applications.

FIG. 5A depicts a flat, planer substrate 500A having an outer surface502 and a thickness 504. FIG. 5B is a cylindrical or tubular poroussubstrate 500B having an outer surface 502 and a thickness 504.

Porous substrates can have any form or shape, for example a flat planershape, a cylindrical or tubular shape, or any other shapes as commonlyknown in the art. Dimensions of porous substrates can be variedaccording to a particular application. For example, the wall thickness504 can be varied as well as the length, width, diameter etc. Theparticular dimensions can be varied along the substrate's length, widthor across the substrates surface 502. For example, FIG. 5C shows atubular porous substrate 500C where the diameter varies along thesubstrate length, forming a “dog-bone” shape.

Porous substrates can be comprised of various materials such as ePTFE,fabrics, silk, Kevlar® brand fibers, or other materials known in thearts. A “porous substrate” is defined as a substrate having openings orpores which may be interconnected. Shown in FIGS. 6A through C aremagnified partial views of the surface of a porous substrate. Shown inFIG. 6A is a porous substrate 600A having nodes 602 interconnected byfibrils 604. The openings or pores are shown as 606A. Porous substratesof this type would be similar to any expanded polymer. Similarly, shownin FIG. 6B is a porous substrate 600B comprised of a solid material 608having openings or pores 606B. Porous substrates of this type would besimilar to any biocompatible plastic. Openings or pores would be formedby mechanical or etching means. Other opening or pore forming means inplastics are commonly known in the art. Shown in FIG. 6C is a poroussubstrate 600C comprised of fibers or filaments 610, having openings orpores 606C. Porous substrates of this type would be similar to those ofwoven fabrics or those woven or formed of fibers.

Porous substrates may be filled with a substance such as a polymer. Thepolymer used for filling openings or pores may be the same as thepolymer of the substrate or of a different polymer. Shown in FIGS. 7Athrough C are magnified partial views of the surface of a poroussubstrate filled with a substance. FIG. 7A shows a porous substrate 700Ahaving nodes 602 interconnected by fibrils 604 and filled pores 702.FIG. 7B shows a porous substrate 700B comprising a solid material 608and filled pores 704. Shown in FIG. 7C is a porous substrate 700C havingfibers 610 and filled openings or pores 706.

FIG. 8 illustrates another embodiment of the invention. A sheath 800similar to sheath 102 is attached to front fitting 802. Sheath 800 maybe of similar dimension and material as that of sheath 102 but isconstructed with a cuff at the proximal most end. Front fitting 802 maythen be formed around or attached to sheath 800. Attachment methods arewell known in the art and may include adhesive or insert molding. Frontfitting 802 may be formed of similar materials to that of front fitting106. Front fitting will be recognized to have similar features andadvantages as that of front fitting 106 including gripping protrusion107 (not shown) and flush port 109 with fitting. Snap ring 108, outertube 110, inner tube 200 and pressurizable space 206 have beenpreviously described in detail. Rear snap ring 108′ is constructed ofmaterials similar to that of snap ring 108′ with fill port 112 and hasfeatures similar to that of snap ring 108′ with fill port 112. Rear snapring 804 may have a featured fill port but preferably does not include afill port. Pressurizable space 206 may be filled upon assembly utilizinga specialized apparatus. Filling materials have been describedpreviously.

EXAMPLES

Without intending to limit the scope of the invention, the followingexamples illustrate how various embodiments of the invention may be madeand/or used.

Example 1

An introducer sheath valve assembly similar to FIG. 1 was manufacturedusing the following components and assembly process:

Components were fabricated using a rapid prototyping, stereolithography(SLA) process. The parts were fabricated by ProtoCam (Northampton, Pa.)using an SLA material designated as Accura® 25 plastic. This materialwhen cured had an advertised tensile strength of about 38 Mpa, a tensilemodulus of about 1590-1660 Mpa, an elongation to break of about 13-20%and a hardness of about 80 Shore D. The tensile and elongation data werederived using test method ASTM D 638. Five parts were fabricated usingthis SLA process and Accura® 25 plastic material. The parts included athreaded adapter, front fitting, snap ring with fill port, and a rearfitting.

Other materials required for the assembly of the introducer sheath valvewere purchased items. A silicone o-ring having a round cross sectionalshape with an outer diameter of about 14 mm, an inner diameter of about12 mm, and a width of about 1 mm was procured from McMaster-Carr (SantaFe Springs, Calif.). FEP rings were fabricated and cut to have an outerdiameter of about 12.7 mm (0.475 inches), an inner diameter of about10.5 mm (0.415 inches), and a thickness of about 0.76 mm (0.030 inches).FEP sheet used to fabricate the rings was procured from Saint-Gobain(Hoosick Falls, N.Y.). The outer tube was manufactured using a moldmaking rubber for prototype designs, Silastic® T-4 Base/Curing Agent,which was ordered from Dow Corning (K.R. Anderson, Inc. Morgan Hill,Calif.). The material when cured had an advertized tensile strength ofabout 970 psi, a tear strength of about 150 ppi, a hardness of about 40Shore D, and an elongation at break of about 390%. The tear strengthdata was derived using test method ISO 34. Sheaths used for theconstruction of this device were either FEP or extruded high-densitypolyethylene with outer diameters ranging from about 7.52 mm to 7.70 mm,and inner diameters ranging from about 6.71 mm to 5.76 mm and wereobtained from various suppliers. Polyvinyl chloride (PVC) tubing havingan outer diameter of about 2.7 mm (0.107 inches), an inner diameter ofabout 1.7 mm (0.068 inches), and a length of about 19.05 cm was obtainedfrom in house stock. A stainless steel mandrel (used to construct theinner tube) having a diameter of about 11.0 mm and a length of about304.8 mm was supplied from in-house stock. A three way polycarbonatestop cock valve with a standard luer fitting was supplied from in-housestock. A quick set cyanoacrylate adhesive and a two part polyurethaneadhesive were supplied from in-house stock. A Sharpie® fine pointpermanent marker was procured from in-house stock.

The introducer sheath valve was then assembled using the componentsdescribed above. For the sheath assembly the non-threaded end of thethreaded adapter was glued onto the proximal end of the sheath using atwo part polyurethane adhesive. The silicone o-ring was then placed in agroove on the threaded end of the threaded adapter.

For the outer tube assembly, an hourglass shaped silicone tube (outertube) was insert molded using Silastic® T-4 around the snap ring withfill port. The Silastic® T-4 was mixed per manufacturer's instructions,degassed as commonly known in the art, and poured into a custom two partmold housing the snap ring with fill port and the snap ring with fillport and cured. Curing time was a minimum of about 1 hour at about 75degrees Celsius. Insert molding was performed in-house as commonly knownin the art. The outer tube assembly was then removed from the mold andflash removed. The final outer tube dimensions were a tube wallthickness of about 2.7 mm, a largest outer diameter of about 17.8 mm,and a smallest outer diameter (at the smallest portion of the hourglassshape) of about 12.75 mm and a length of about 22.5 mm.

The inner tube assembly was then constructed using a thin porous ePTFEmembrane. The thin porous ePTFE membrane was constructed as per U.S.Patent Publication No. 2007/0012624 A1 or U.S. Patent Publication No.2008/0053892 A1. The thin porous membrane was rolled onto the stainlesssteel mandrel for five complete wraps then cut. On the same roll, a thinmembrane produced according to the teachings of U.S. Pat. No. 7,049,380was rolled for two complete wraps then cut. The thin porous ePTFEmembrane was then rolled for another five complete wraps then cut. Thefinal thickness of the construct was about 30 microns. FEP rings werethen manually stretched over a Sharpie® fine point permanent marker,removed from the marker and placed on the wrapped tube construct atabout 32.5 mm inner ring to inner ring intervals. The assembly was thenplaced in an ESPEC laboratory oven (model number STPH-201) at about 320degrees Celsius for about 14 minutes. The assembly was then removed fromthe oven and allowed to cool to room temperature. The assembly was thenstripped off the mandrel and segments were cut to include two FEP ringsper segment.

The inner tube assembly was then inserted through the outer tubeassembly such that the FEP rings extended from each end of the outertube assembly. The FEP ring on the snap ring with fill port side wasfitted over the protruding diameter of the front fitting. Cyanoacrylateadhesive was applied to the inner surface of the snap ring. The frontfitting and the outer tube assembly were snapped together by hand. Theremaining FEP ring was fitted over the protruding diameter of the rearfitting. Cyanoacrylate adhesive was applied to the inner surface of thesnap ring with fill port and the rear fitting and snap ring with fillport were snapped together by hand.

The valve assembly was then threaded onto the sheath assembly. The PVCtubing was adhered to the fill port with cyanoacrylate adhesive and athree way stopcock valve was attached to the end of the tubing. Thepressurizable space between the outer tube and the inner tube waspressurized through the stopcock valve to the desired pressure beforetesting using a syringe filled with water.

This example of the introducer sheath valve may be provided in aprefilled configuration by pressurizing the space between the outer tubeand the inner tube and then using a plug or plugging substance toocclude the fill port.

Example 2

An introducer sheath valve assembly similar to FIG. 8 was manufacturedusing the following components and assembly process:

The parts were fabricated by ProtoCam (Northampton, Pa.) using an SLAmaterial designated as Accura® 25 plastic. This material when cured hadan advertised tensile strength of about 38 Mpa, a tensile modulus ofabout 1590-1660 Mpa, an elongation to break of about 13-20% and ahardness of about 80 Shore D. The tensile and elongation data werederived using test method ASTM D 638. Three parts were fabricated usingthis SLA process and Accura® 25 plastic material. The parts included twosnap rings and a rear fitting.

Other materials required for the assembly of the introducer sheath valvewere purchased items. The front fitting was manufactured in-house usinga urethane plastic for prototype designs, Smooth-Cast® 300 urethane,which was ordered from ProtoCam (Northampton, Pa.). This material whencured had an advertised tensile strength of about 3,000 psi and ahardness of about 70 Shore D. A silicone o-ring having a round crosssectional shape with an outer diameter of about 14 mm, an inner diameterof about 12 mm, and a width of about 1 mm was procured fromMcMaster-Carr (Santa Fe Springs, Calif.). FEP rings were fabricated inhouse and cut to have an outer diameter of about 12.7 mm (0.475 inches),an inner diameter of about 10.5 mm (0.415 inches), and a thickness ofabout 0.76 mm (0.030 inches). FEP sheet used to fabricate the rings wasprocured from Saint-Gobain (Hoosick Falls, N.Y.). The outer tube wasmanufactured in-house using a mold making rubber for prototype designs,Silastic® T-4 Base/Curing Agent, which was ordered from Dow Corning(K.R. Anderson, Inc., Morgan Hill, Calif.). The material when cured hadan advertized tensile strength of about 970 psi, a tear strength ofabout 150 ppi, a hardness of about 40 Shore D, and an elongation atbreak of about 390%. The tear strength data was derived using testmethod ISO 34. The sheaths used for the construction of this device wasextruded high-density polyethylene with outer diameters ranging fromabout 7.52 mm to 7.70 mm, and inner diameters ranging from about 6.71 mmto 5.76 mm and was procured from in-house stock. A stainless steelmandrel (used to construct the inner tube) having a diameter of about11.0 mm and a length of about 304.8 mm was supplied from in-house stock.A quick set cyanoacrylate adhesive and a two part polyurethane adhesivewere supplied from in-house stock. A Sharpie® fine point permanentmarker was procured from in-house stock.

The introducer sheath valve was then assembled using the componentsdescribed above. To make the sheath assembly, the polyethylene sheathwas RF (radio frequency) formed to create a cuff at the proximal mostend. The cuff was approximately 0.94 mm thick and had an outer diameter8.59 mm. The front fitting was insert molded over the cuff on the sheathusing Smooth-Cast® 300 urethane. Smooth-Cast® 300 was mixed permanufacture's instructions and poured into a custom two-part mold.Insert molding was performed in-house as commonly known in the art. Theassembly was then removed from the mold and flash removed.

For the outer tube assembly, an hourglass shaped silicone tube (outertube) was molded using Silastic® T-4 silicone. The Silastic® T-4 wasmixed per manufacture's instructions, degassed as commonly known in thearts, and poured into a custom two-part mold and cured. Curing time wasa minimum of about 1 hour at about 75 degrees Celsius. Insert moldingwas performed in-house as commonly known in the art. The outer tube wasthen removed from the mold and flash removed. The final outer tubedimensions were a tube wall thickness of about 2.7 mm, a largest outerdiameter of about 17.8 mm, and a smallest outer diameter (at thesmallest portion of the hourglass shape) of about 12.75 mm and a lengthof about 22.5 mm. The snap rings were snapped onto the ends of thesilicone tube. The silicone tube edges were lifted and a cyanoacrylateadhesive was applied between the edge of the silicone tube and the snapring. The assembly was then placed at room temperature until theadhesive was fully cured according to manufacturer's instructions.

The inner tube assembly was made according to the method described inExample 1.

The inner tube assembly was then inserted through the outer tubeassembly such that the FEP rings extended from each end of the outertube assembly. Cyanoacrylate adhesive was then applied to the protrudingdiameter of the front fitting on the sheath assembly and the FEP ringwas fit over the protruding diameter of the front fitting. Cyanoacrylateadhesive was applied to the inner surface of a snap ring on the outertube assembly. The front fitting and outer tube assembly were snappedtogether by hand. Cyanoacrylate adhesive was applied at the base of theprotruding diameter of the rear fitting. The remaining FEP ring wasfitted over the protruding diameter of the rear fitting.

The pressurizable space between the outer tube and the inner tube wasthen pressurized with glycerin. In order to pressurize the space withglycerin, the valve assembly was placed in an in-house made fixture. Thefixture consisted of a movable housing to grasp the rear fitting and astationary housing to grasp the snap ring and outer tube assembly. Thisfixture maintained a gap of approximately 2.0 mm between the rearfitting and the snap ring during pressurizing. The fixture alsoconsisted of a cuff containing two o-rings on its interior with adiameter designed to form a tight seal around the rear fitting and thesnap ring. The cuff was fitted with an aperture extending through thecuff and a tube connected to the aperture. The tube was connected to asyringe filled with glycerin. The cuff was fitted over the gap betweenthe rear fitting and the snap ring and the pressurizable space wasfilled with glycerin to the desired pressure. Once the space was filled,and while the cuff was still fitted over the gap between the rearfitting and the snap ring, the movable housing was pushed toward thesnap ring to close the gap. Excess glycerin was removed from the outsideof the introducer sheath valve assembly.

While particular embodiments of the present invention have beenillustrated and described herein, the present invention should not belimited to such illustrations and descriptions. It should be apparentthat changes and modifications may be incorporated and embodied as partof the present invention within the scope of the following claims.

1. An introducer sheath valve comprising: an outer tube; an inner tubecomprised of porous substrate; and a pressurizable space formed betweenan inner surface of the outer tube and an outer surface of the innertube.
 2. The introducer sheath valve of claim 1, wherein the poroussubstrate comprises a polymer.
 3. The introducer sheath valve of claim1, further comprising at least one polymer filling at least a portion ofthe porous substrate.
 4. The introducer sheath valve of claim 2, furthercomprising at least one polymer filling at least a portion of the poroussubstrate.
 5. The introducer sheath valve of claim 1, wherein thepressurizable space is pressurized with at least one substance to asufficient pressure to cause the inner tube to collapse.
 6. Theintroducer sheath valve of claim 5, wherein the pressure is sufficientto prevent back bleeding.
 7. The introducer sheath valve of claim 5,wherein at least one interventional device can be advanced through theinner tube.
 8. The introducer sheath valve of claim 1, wherein the innertube comprises a lubricious material.
 9. The introducer sheath valve ofclaim 1, wherein the inner tube comprises a material selected from thegroup consisting of ePTFE (expanded polytetrafluoroethylene), fabrics,silk, and Kevlar®.
 10. The introducer sheath valve of claim 9, whereinthe inner tube comprises ePTFE.
 11. The introducer sheath valve of claim5, wherein the at least one substance comprises a material selected fromthe group consisting of air, silicone, water, saline solution, lowvolatility biocompatible liquids, glycerin, propylene glycol,polyethylene glycol, compressible foam, elastomeric spheres, andcrosslinked silicone gels.
 12. The introducer sheath valve of claim 1,wherein the pressurizable space is formed by sealing a first end of theouter tube to a first end of the inner tube and sealing a second end ofthe outer tube to a second end of the inner tube.
 13. The introducersheath valve of claim 12, wherein the sealing is accomplished by atleast one of the following: interference fit, adhesion, thermal bond,and insert molding.
 14. The introducer sheath valve of claim 13, whereinthe interference fit is formed using at least one o-ring.
 15. Theintroducer sheath valve of claim 1, wherein the pressurizable spacemaintains a pressure wherein the pressure is attained by an externalsource.
 16. The introducer sheath of claim 15, where in the pressure isattained by at least one of the following: finger pressure, a leafspring, and filled syringe.
 17. An introducer sheath valve comprising:an outer tube; an inner tube having a thickness of about 0.0025 mm toabout 1 mm; and a pressurizable space formed between an inner surface ofthe outer tube and an outer surface of the inner tube.
 18. Theintroducer sheath valve of claim 17, wherein the porous substratecomprises a polymer.
 19. The introducer sheath valve of claim 17,further comprising at least one polymer filling at least a portion ofthe porous substrate.
 20. The introducer sheath valve of claim 18,further comprising at least one polymer filling at least a portion ofthe porous substrate.
 21. The introducer sheath valve of claim 17,wherein the pressurizable space is pressurized with at least onesubstance to a sufficient pressure to cause the inner tube to collapse.22. The introducer sheath valve of claim 21, wherein the pressure issufficient to prevent back bleeding.
 23. The introducer sheath valve ofclaim 21, wherein at least one interventional device can be advancedthrough the inner tube.
 24. The introducer sheath valve of claim 17,wherein the inner tube comprises a lubricious material.
 25. Theintroducer sheath valve of claim 17, wherein the inner tube comprises amaterial selected from the group consisting of ePTFE, fabrics, silk, andKevlar®.
 26. The introducer sheath valve of claim 25, wherein the innertube comprises ePTFE.
 27. The introducer sheath valve of claim 21,wherein the at least one substance comprises a material selected fromthe group consisting of air, silicone, water, saline solution, lowvolatility biocompatible liquids, glycerin, propylene glycol,polyethylene glycol, compressible foam, and crosslinked silicone gels.28. The introducer sheath valve of claim 17, wherein the pressurizablespace is formed by sealing a first end of the outer tube to a first endof the inner tube and sealing a second end of the outer tube to a secondend of the inner tube.
 29. The introducer sheath valve of claim 28,wherein the sealing is accomplished by at least one of the following:interference fit, adhesion, thermal bond, and insert molding.
 30. Theintroducer sheath valve of claim 29, wherein the interference fit isformed using at least one o-ring.
 31. The introducer sheath valve ofclaim 17, wherein the pressurizable space maintains a pressure whereinthe pressure is attained by an external source.
 32. The introducersheath of claim 31, wherein the pressure is attained by at least one ofthe following: finger pressure, a leaf spring, and filled syringe. 33.An introducer sheath valve comprising: an outer tube; an inner tubecomprising ePTFE; and a pressurizable space formed between an innersurface of the outer tube and an outer surface of the inner tube. 34.The introducer sheath valve of claim 33, wherein the porous substratecomprises a polymer.
 35. The introducer sheath valve of claim 33,further comprising at least one polymer filling at least a portion ofthe porous substrate.
 36. The introducer sheath valve of claim 34,further comprising at least one polymer filling at least a portion ofthe porous substrate.
 37. The introducer sheath valve of claim 33,wherein the pressurizable space is pressurized with at least onesubstance to a sufficient pressure to cause the inner tube to collapse.38. The introducer sheath valve of claim 37, wherein the pressure issufficient to prevent back bleeding.
 39. The introducer sheath valve ofclaim 37, wherein at least one interventional device can be advancedthrough the inner tube.
 40. The introducer sheath valve of claim 37,wherein the at least one substance comprises a material selected fromthe group consisting of air, silicone, water, saline solution, lowvolatility biocompatible liquids, glycerin, propylene glycol,polyethylene glycol, compressible foam, and crosslinked silicone gels.41. The introducer sheath valve of claim 33, wherein the pressurizablespace is formed by sealing a first end of the outer tube to a first endof the inner tube and sealing a second end of the outer tube to a secondend of the inner tube.
 42. The introducer sheath valve of claim 41,wherein the sealing is accomplished by at least one of the following:interference fit, adhesion, thermal bond, and insert molding.
 43. Theintroducer sheath valve of claim 42, wherein the interference fit isformed using at least one o-ring.
 44. The introducer sheath valve ofclaim 33, wherein the pressurizable space maintains a pressure whereinthe pressure is attained by an external source.
 45. The introducersheath of claim 44, wherein the pressure is attained by at least one ofthe following: finger pressure, a leaf spring, and filled syringe.
 46. Amethod of assembling an introducer sheath valve comprising: (a)providing an outer tube; (b) attaching a snap ring one end of the outertube and attaching a snap ring will fill port to another end of theouter tube forming an outer tube assembly; (c) attaching a ring to eachend of an inner tube forming an inner tube assembly; (d) threading theinner tube assembly through the outer tube assembly; (e) attaching theinner tube assembly to a front fitting; (f) snapping the outer tubeassembly onto the surface of the front fitting; (g) attaching the innertube assembly to a rear fitting; (h) snapping the snap ring with a fillport on the outer tube assembly and the rear fitting closed; (i) fillinga pressurizable space through the fill port prior to use.
 47. A methodof assembling an introducer sheath valve comprising: (a) providing anouter tube; (b) attaching a snap ring one end of the outer tube andattaching a snap ring will fill port to another end of the outer tubeforming an outer tube assembly; (c) attaching an inner tube to a frontfitting; (d) threading the inner tube through the outer tube assembly;(e) snapping the outer tube assembly onto the surface of the frontfitting; (f) attaching the inner tube to a rear fitting; (g) snappingthe snap ring with fill port on the outer tube assembly and the rearfitting closed; (h) filling a pressurizable space through the fill portprior to use.
 48. A method of assembling an introducer sheath valvecomprising: (a) providing an outer tube; (b) attaching a snap ring toboth ends of the outer tube forming an outer tube assembly; (c)attaching a ring to each end of an inner tube forming an inner tubeassembly; (d) threading the inner tube assembly through the outer tubeassembly; (e) attaching the inner tube assembly to a front fitting; (f)snapping the outer tube assembly onto the surface of the front fitting;(g) attaching the inner tube assembly to a rear fitting; (h) fillingwith a substance a space formed between the inner tube and the outertube assembly; (i) snapping the snap ring on the outer tube assembly andthe rear fitting closed; (j) removing all excess fluid from the outertube housing unit.
 49. A method of assembling an introducer sheath valvecomprising: (a) providing an outer tube; (b) attaching a snap ring toboth ends the outer tube forming an outer tube assembly; (c) attachingan inner tube to a threaded adapter; (d) threading the inner tubethrough the outer tube assembly; (e) snapping the outer tube assemblyonto the surface of the threaded adaptor; (f) attaching the inner tubeto a rear fitting; (g) filling with a substance a space formed betweenthe inner tube and the outer tube housing; (h) snapping the inner tubeand the rear fitting closed; (i) removing all excess fluid from theouter tube housing unit.